Air conditioning systems require energy for raising and lowering air temperature and which can be assisted by the storage of "solar insolation" heated liquid and/or conversely by the storage of chilled liquid, and also assisted by absorption from or into the surrounding ambient air. The collection of solar heat energy is normally within a range of nominally 100.degree. to 180.degree. F. or higher, while the heat pump can be assisted from a water source within a range of 55.degree. to 90.degree. F.; and to these ends I have provided a stratified thermal mass wherein the solar heat is stored at high to low temperatures, from which the heat pump withdraws heat at moderate temperatures of 55.degree. to 90.degree. F., and wherein residual heat at low temperatures is utilized for auxiliary purposes such as to pre-heat a domestic hot water supply or the like.
It is substantially total environmental assistance for one or more liquid or water source heat pumps with which the present invention is concerned, a comprehensive concept which involves the conservation of energy, both by collection of all available heat sources, including solar insolation, terrestrial re-radiation, auxiliary absorption, and assisted by heat absorption to or from and from within the system under whatever conditions. The more or less predictable collection of solar energy in a thermal mass is variable to say the least, and water source heat pumps have a practical operating range, at times below the temperature of said thermal mass storage of solar energy and at times above said thermal mass temperature, at whatever temperature variant said mass might be above or below the range of normal heat pump operation. That is, there will be times when the remaining solar energy stored in the thermal mass is less than said 55.degree. F. minimum, and times when it is more than said 90.degree. F. maximum. To this end, therefore, the thermal mass is stratified in accordance with my invention as it is disclosed and claimed in my U.S. Pat. No. 3,996,759 issued Dec. 14, 1976 entitled ENVIRONMENT ASSISTED HYDRONIC HEAT PUMP SYSTEM. To this end, convertible solar panels are employed and from which heat is collected and discharged, the collected heat being progressively absorbed into a thermal mass as the liquid transfer media moves toward the low heat range section, and to and from which heat is exchanged into and from the atmosphere when heat is in excess or deficient within the system, respectively.
The application and withdrawal of heat into and from the stratified thermal mass storage is by means of closed loop pumping circuits and through a mixing or proportioning valve to assist the heat pump, whereby the said water source to the heat exchanger is controlled within the 55.degree. to 90.degree. F. water source range as by means of a thermostat control over said valve. In accordance with the invention provision is made for extraordinary conditions, one to apply heat as by the application of external energy and the other to remove heat. Studies have shown that heat pumps consume far less purchased energy than other conventional heating, ventilating and air conditioning systems employed to heat and cool buildings. Significant improvements in performance and reliability in heat pumps have been made and with energy problems and the escalating costs of energy, present day heat pumps are more economical than ever before, and all of which is of increasing concern to utility planners now desperately attempting to maximize the use of power generation. Since heat pumps utilize more readily available and useable low temperature energy sources, further reductions in purchased energy consumption by heat pumps during normal heating periods is a general object of this invention.
The conventional reversible-cycle heat pump is similar to a refrigeration machine and has the same basic components, namely a compressor, condensor and evaporator. In the operation of a typical "air-to-air" heat pump, outside air has a useful heat content even at lower temperatures, resulting in free heat that makes it possible for the heat pump to supply more energy than it consumes; with a high heating coefficient of performance (COP.sub.H), i.e., the ratio of useful heat output to electrical energy input apparently 2.0 which falls off rapidly at ambient air temperatures below 40.degree. F. Consequently, the heat pump has the lowest operating cost of any present day electrical heating/cooling equipment, providing that a useful heating source is made available throughout a substantial portion of the operating hours. The same advantage is available with "water source" heat pumps with which this invention is preferably concerned. Therefore, it is an object of this invention to advantageously employ such heat sources as the underlying earth, the surrounding atmosphere, solar radiation, and auxiliaries such as space lighting etc. within the building to be conditioned. As a result, there is an unexpected increase in the COP.sub.H in the operation of said water source heat pump, for substantial energy saving during both the heating periods of the day and night.
Low temperature heat sources such as the earth and the surrounding atmosphere are useful energy sources when combined with a heat pump capable of utilizing the same to increase performance. It is preferred therefore to employ a water source heat pump that advantageously utilizes water heated to a low temperature by the ground temperature ambient of about 55.degree. F., and water heated by the air ambient of about 55.degree. to 80.degree. F. as the case may be. It is an object therefore to provide means to acquire a water source at the ground ambient of about 55.degree. F., in practice a heat exchange well sunk into the earth a substantial depth. It is another object therefore, to provide means to acquire auxiliary heat at temperatures of about 50.degree. to 80.degree. F. It is also an object therefore to provide water-to-air heat pump temperature transfer of 55.degree. to 90.degree. F., and to provide water-to-air radiation into the atmosphere as well as air-to-water re-radiation at prevailing temperatures as circumstances require. With the present invention, the heat pump unit has an auxiliary heat transfer intake coil ahead of the condensor when in the Heat Mode, and ahead of the evaporator when in the Cool Mode.
Solar assisted heat pumps conserve energy by combining the thermodynamic features of a heat pump with the relatively low temperatures (50.degree. to 90.degree. F.) readily available from flat plate solar collectors, it being an object of this invention to provide a balance between solar energy generation and its utilization. In practice, solar panels collect heat up to about 160.degree. F., and it is therefore an object to proportion this heat source with chilled water for maintaining operational water in the range of 55.degree. to 90.degree. F. It is another object to provide storage for both heated and chilled water, the latter to be employed during the cooling cycle so as to assist and permit a reduction in power demand, for example to reduce summer demand peaks that are often experienced by electrical utilities. It is also an object to provide a modular solar panel installation which establishes an integral roof structure, and which is convertible for both heat absorption and heat rejection.
Air conditioning systems of the type under consideration are used for commercial as well as residence buildings, and very often produce waste heat when operating in the cool mode. Normally, this waste heat is discharged into the atmosphere by means of a cooling tower, an air cooled condensor or heat exchanger. In the case of solar assisted systems, for example, glazed panels are employed for the absorption of energy from the sun during the day, whereas unglazed panels are employed for re-radiation into the atmosphere during the night; and where such panels are employed for both absorption and re-radiation, unglazed panels are used as a compromise less efficient than those that are glazed. Since the function of a cooling tower is to discharge heat the same as the unglazed solar panel used for re-radiation, it is an object herein to provide means by which a solar panel is convertible from a glazed condition to an unglazed condition, so as to be as efficient as possible in either of the aforesaid conditions and functions thereof. In practice, glass louvers are employed to shift from a closed hot-house condition to an open ventilating condition, the glass louvers being cross sectioned as required, as for example as a lens form for the collection of direct light in the solar mode; flat glass being preferred for indirect lighting. It is to be understood that any combination of flat and/or lens shaped glass can be employed as circumstances require. As a result, the need for a conventional cooling tower is eliminated.
The environmental assisted heat pump presents the advantage of combining efficient heating and cooling capabilities into a single integrated unit, it being an object to practice an economical means of re-distributing captured energy from low temperature heat sources including solar heating. As a result, heat coefficient of performance (COP.sub.H) in the Heating Mode is high, while cooling demands in the Cooling Mode are reduced through the assistance of applying chilled water ahead of the condensor and/or behind the evaporator, depending upon whether excess cooling capacity is extracted for storage or delivered from storage, as the case may be. Accordingly, it is an object of this invention to advantageously employ said performance efficiency by reducing the size or performance capacity (minimizing the same) of the heat pump unit, relying upon the assistance afforded by maximized heat energy conservation. As a result, there is a substantial savings realized within the operation of this integrated conditioning system, all as hereinafter described.
The installation of solar heat collectors has required field labor for the involved piping therefor, and which accounts for as much as half the cost; and to this end it is an object of this invention to modularize solar panels which are complementary to each other without additional piping and to consolidate substantially all pumps, valves and related plumbing within a Control Center. In carrying out this invention, the panels mate one with the other with the use of interconnecting nipples that are selectively employed in place of plugs that are removed as circumstances require, and all of the cooperatively related components are plumbed to a common Control Center.